In road construction, for example, generic road pavers or feeders, hereinafter summarized as road construction machines, are used for laying base layers, for example concrete or asphalt layers. If the paving material is laid using a road paver, the feeder serves as an intermediate storage and for the transfer of paving material in the paving process. During the paving process, the road paver is supplied with paving material either directly by a transport vehicle, for example a truck, or via a feeder. When a feeder is involved, this feeder is supplied with paving material from a transport vehicle, and transfers said material to the road paver via a suitable conveyor device, typically a conveyor belt. Typically, these road construction machines are self-propelled. Both the road paver and the feeder comprise a machine frame and a chassis, for example comprising crawler tracks or wheels, which is driven by a drive unit, which may be a diesel combustion engine in most cases. A material hopper is provided at the front in the working direction of the road construction machine. The working direction of the road construction machine refers to the direction in which the road construction machine travels during working or paving operation. The material hopper is a storage space for paving material, the size of which can be increased and/or decreased by displacing and/or tilting the walls of the material hopper. The paving material is conveyed by the road construction machine from the material hopper via a conveyor device, for example a scraper belt, to the rear, where, in the case of a feeder, a conveyor is arranged, which transfers the paving material from the feeder to the road paver. In the case of a road paver, the machine comprises at its rear a transverse conveyor device, for example a screw conveyor, and a screed, via which the paving material is distributed, smoothened and pre-compacted across the entire paving width. A smooth, pre-compacted layer of the paving material is left behind the road paver, which can be further compacted by means of rollers, for example, in order to achieve a finished road.
The transfer of the paving material from the transport vehicle, in particular a truck, to the generic road construction machine, whether feeder or road paver, is in each case done in the same way. A truck loaded with the paving material backs until being directly in front of the road construction machine traveling in the working direction, and stops there. Now, a controlled collision between the two vehicles is effected. To that end, collision rolls may be provided on the end of the construction machine located in the front in the working direction, the rolls getting in contact with the rear of the transport vehicle as the road construction machine advances slowly. The road construction machine then pushes along the transport vehicle via the collision rolls while the paving process of the road paver is continued. The transport vehicle can then transfer the paving material into the material hopper of the road construction machine, which is located at the front in the working direction, by tilting the loading area to the rear. Once the transfer is completed, the loading area can be lowered, and the transport vehicle drives away in the forward direction.
In order to ensure the complete emptying of the hopper, the hopper typically comprises a discharge flap. The discharge flap accounts for the main part of the hopper base and further comprises flap side walls, which are located at the periphery transversely to the working direction, the flap side walls extending next to the inner side of the hopper side wall and being fastened to the flap base. Thus, the flap side wall vertically protrudes upward from the hopper base substantially parallel to the hopper side wall extending in the working direction. Typically, it is supported to be moveable in relation to the hopper side wall. In order to put paving material located on the discharge flap completely into the conveyor device of the road paver or feeder for further processing, the discharge flap is designed to be pivotable about a pivot axis extending transversely to the working direction. The discharge flap, together with the flap base and flap side walls, can thus be pivoted vertically upward and against the working direction about the pivot axis extending transversely to the working direction. As a result of this movement, paving material located on the discharge flap is dumped into the conveyor device of the road paver or feeder, which is located behind the material hopper in the working direction. In this way, the material hopper can be completely emptied of paving material.
As already indicated above, the flap side wall extends vertically upward from the flap base next to the hopper side wall. The hopper side wall refers to the lateral boundary of the entire hopper space. The side of the hopper side wall located outward transversely to the working direction forms part of the outer contour of the road paver or feeder. In contrast, the flap side wall is located inside the material hopper next to the hopper side wall. It goes without saying that such an arrangement of hopper side wall and flap side wall is present on both sides of the material hopper. In the working mode of the road paver or feeder, the flap side wall and the hopper side wall either directly rest against one another or are spaced from one another by a narrow gap. In practice, paving material will often enter the gap between the flap side wall and the hopper side wall. The entered paving material spreads the flap side wall from the hopper side wall and increases the gap between the two side walls. In this way, the intrusion of additional paving material between the two side walls is facilitated, and the gap between the flap side wall and the hopper side wall is further increased. In this way, paving material may on the one hand fall between the hopper side wall and the flap side wall onto the ground. Moreover, paving material may jam between the hopper side wall and the flap side wall, which leads to a jamming of the flap side wall or the discharge flap per se, whereby its function is limited. Insistently jammed paving material may also result in a deformation of the discharge flap in this region, and thus in a damage.